package.json fields for exports

package-json-exports.json5

{
  
  // Support for native ESM (official)
  // See <https://nodejs.org/api/packages.html#packages_type>
  "type": "module",
  
  // Export map (official)
  // See <https://nodejs.org/api/packages.html#packages_subpath_exports>
  "exports": {
    ".": {
      "require": "./index.cjs", // Good old CJS
      "import": "./index.js" // Brand new ESM
    }
  },
  
  // Export (unofficial)
  // See <https://github.com/rollup/rollup/wiki/pkg.module>
  "module": "./index.js", // Brand new ESM
  
  // Export (unofficial?)
  "main": "./index.cjs", // Good old CJS
  
  // TypeScript typings (official)
  // See <https://www.typescriptlang.org/docs/handbook/declaration-files/publishing.html#including-declarations-in-your-npm-package>
  "types": "index.d.ts",
}